Gas Burners for Forges Furnaces and kilns phần 6 potx

They are centered and squared with a tube forge sitting on them, and then the 114- 20 screws are used to attach both runners to the cart's top angles.. After you find a place where the c

Gas Burners 6

Now use the left over foot of board, along with one of the bricks (as well as the Mullite tiles if any) to show how much more Perlite is needed to top off that layer Compress the Perlite flat in each area and sprinkle more around (compressing it) until the brick slides under the angle with resistance In the confined area around the burner collar, use the brick in place of the board and the cut out plug in place of the brick When you are sure the Perlite layer is flat and the right height, install the first board Measure the width of the open area and add 114-inch Cut the second board the same length as the first board Force the second board into place Replace the end angle

The bricks are placed facing across the width of the tabletop for most of its length Push down on the pallet (the proper term for ceramic board used this way) and slip the first brick into a corner Use the pipe clamp to force it under the lip of the top angles Place the second brick beside the first using the pipe clamp to pull the first brick clear and then to move the second brick into position Place the bricks beside one another, working your way across the tabletop until you are close to the

Fig 6-13 Looking down into the refractory portal, a darkened ring of tapered wall stops at the shoulder left by the glass votive candle form (or small flower pot), then continues narrowing,

to end in a thin shoulder sur- rounding the edge of the steel tube Near the bottom of the tube three of the thumbscrews pro- trude above the drain bottom

burner collar At this point decide which kind of burner port you will use If the poured refractory is employed, then place the rest of the brick about two inches away from the collar, forming a square (the brick cuts easily using a hacksaw) If the burn-

er port is cut into the brick, then saw and file each brick to form a tapered opening

as you place them

The vertical fiber blanket layer acts as a spring, forcing the brick together But it will eventually take a set At this point the bricks can be mortared together if desired

To do so, remove the top angle as needed and mortar the bricks a section at a time Remember the refractory will air set in about twenty minutes Afterward, the top face should be plastered with the mortar and heat cured

Accessories

The gas control panel mentioned in Chapter 5 should be mounted on the side screen below the tabletop, attached with flat washers and machine screws from inside the

Buildinn the F o r ~ e Cart

screen Copper tube can be run from the gas manifold up to the burner A "tee" fit- ting, ball valve, and copper tube can connect a permanently located auxiliary hose with a quick coupler to a hand torch or tabletop burner

Work rack for tube forge

Work should be placed on a crossbar outside the forge This helps protect the shelf against abuse, and reduces heating time It is better for the material rack's crossbar to

be several inches away from the exhaust, so positioning the bars beyond the edge of the cart makes sense The rack can also be used to secure the tube forge Heavy work must be supported by an independent means to avoid overbalancing the cart

Materials list for rack

(1) Two 118 x 1 114 x 1 114-inch angles, 40-inches long

(2) 118 x 3-inch flat bar, 12-inches long

(3) Twelve 114-20 x 112-inch screws and nuts, plus eight 10-32 x 1 112-inch screws (4) Two pieces of 318-inch allthread, 12-inches long, and eight 318-inch nuts

(5) Four replacement carriage bolts, 3-inch long

Plastic triangle

Change out the forge legs with four 3-inch long carriage bolts The two 1 114- inch angles are placed toed up and toed in on the forge cart over the desired area They are centered and squared with a tube forge sitting on them, and then the 114-

20 screws are used to attach both runners to the cart's top angles Holes are drilled and tapped for 10-32 x 1-inch screws on both sides of each carriage bolt head, trap- ping the forge legs on the two angle iron cross pieces

Next, make 9O0marks across the angles where they overhang the forge cart Mark lines at 30" on both sides of the right angle lines, and cut out the 60" wedges Heat and bend the excess angle up Cut four matching wedge shapes out of the 3-inch flat

Fig 6-14 Perspective view of fin-

ished rack Note the cutaway sec-

tion showing the allthread inside

of the pipe roller

Bottle rack

The bottle rack doesn't have to be elaborate Four angle braces bolted to the sheet metal shelf to trap the tank's bottom ring, and a bungee cord attached to the screens will hold your tank securely, during transport

Hose rack

Both fuel hoses require hooks to hang from They can be purchased or made, and can

be screwed onto the side screens in the same manner as recommended for the burn-

er control panel However, if you can find an aluminum angle, say 3 X 5-inch, the hooks can be mounted on it It can be screwed into the sheet metal pan of the table- top and provide support for plumbing from the control panel to the hoses The angle should be placed about one-third the way in, under the tube forge area The hand burner fuel hose must be removed when using the slack tub This is why it is fitted with a quick release coupling

The clamshell forge

The hand burner fuel hose must be removed when using the slack tub This is why it

is fitted with a quick release coupling The cart constitutes about 314 of a clamshell forge's structure It is also the basis for a variable configuration brick forgelkiln The clamshell's lid gets bolted onto the forge cart and can be left in place or taken off and stored when not in use This part is basically a steel shell, and can be recycled out of many things: trashcan lids, steel drum bottoms, or water tank ends

For this example, a sheet metal barbecue shell is used Its aluminum exhaust choke is moved inside the lid and screwed closed Construction methods and tools for a Clamshell lid are covered in Chapter 10 The differences between that model and this one are: (1) Resizing the parts to suit your choice of shell If the lid is larger than the fiber blanket can accommodate, then the blanket is peeled into layers and they are laid cross-wise to each other before being glued into a solid mass with rigidizer (2) It is more convenient and efficient to leave movable spaces in bricks sit- ting on the tabletop for exhaust openings; therefore the lid recesses shown in Chapter

10 are deleted (3) The lid's handle faces to the side instead of forward and is attached

to a rocker arm instead of the lid

A (drilled) round kiln shelf is recommended as a protective cover for the insulat-

ing brick tabletop if no tile is used there Brick sections are used to form a squat ver- tical wall with variable openings, and of any desired height The lid rests upon this wall in the closed position More than one size lid can be used on the same cart More than one size of burner can be used with them and with the variable brick forgelkiln

Building the Forge Cart

Fig 15L Detail of rocker arm assembly in raised position Note the locked double nuts The brass washer can be moved to any of three places to help vary the amount of drag

Fig 16R Clamshell forge with lid in raised posi- tion

The lid's motion coming down is modified with a pressure nut and multiple washers

to create drag This is more than sufficient to hold the lid in any position when a counter-balance, made up of an eyebolt and washers, is hung on one of the rocker arms The weight can later be changed over to a woven steel line and pulleys operat-

ed by a foot pedal

Materials list

(1) Six feet of 118 x 314 x 314-inch steel angle

(2) Six feet of 065-inch wall, 1-inch square tube

(3) Six feet of 118 x 314-inch flat bar

(4) Two 1/4-20 x 1 112-inch thumbscrews

(5) 5/16 x 6-inch allthread, four nuts, two brass flat washers, wing nuts

See Chapter 10 for ceramic materials

Construct the Clamshell lid according to the above discussion Next, bend the flat bar into a "U" shape It can be wider or narrower than the length of the lid's handle You want a loose fit, to allow limited motion for easy leveling Drill 5116-inch holes

in both legs, 12-inch up from the end bend Drill a small hole in the bend's center for

an eyebolt Cut two angles 30-inch long; clamp them together and drill matched 5116-inch holes through the end of one leg in each vertical angle Cut their other legs back to create end tabs, grind the tab faces smooth and round off their corners; place them on the outside of the "U" and assemble them using parts #5, while adjusting the rocker arms to parallel They toe toward the cart so that their inside legs can be jammed against the square tube with thumbscrews, and their toes will miss the screw heads that attach the square tubes to the cart

Gate cut (45" corners) the square tube into two parts long enough to reach from the cart's bottom angle to its top angle Drill and tap a hole for the 114-20 thumb-

Gas Burners 6

screw 5-inch down from the top and facing out (a left and a right) in both tubes

Drill 3116-inch holes through the exposed inner walls of the tubes in the where they

overlap the cart's top and bottom angles Lock the lid assembly in the tubes and place

the lid over the burner port Mark the tube positions, remove the assembly, and screw

one tube to the top angle Replace assembly, lock it above the bottom holes and

attach both tubes to the bottom angle Remove assembly and attach to the last top

screw Replace assembly, drill hole through both arms and both of the lid's handle

sides for #lo-32 screws Attach the rocker arms to the lid handle with left over screws

and nuts from the cart

Purchased carts

Most purchased carts are not strong enough to serve as a dependable worktable The

more substantial models are expensive A standard cart would need partial rebuild-

ing in order to accommodate the features that make it completely serviceable, so you

might as well build the cart yourself If you do choose to buy a "bargain" cart, then

be aware that its shortcomings stem from the very thin sheet metal of its construc-

tion This can be improved by a little reinforcement with metal angle braces below

the area where the slack tub and propane cylinder will rest on the lower shelf Braces

should be placed diagonally across the bottom of the top shelf, one inside and one

outside (crossing in the other direction) Angle should be used to strengthen the legs

of the cart too The angles should be drilled and painted before installation with

machine screws and nuts The leg braces should be employed to trap the expanded

metal sides recommended for this cart They can also extend about six inches higher

than the bottom side of the top shelf Sheet metal walls and angle iron top pieces can

than be employed to build a refractory the tabletop featured in this chapter Such a

top would do much to finish strengthening a purchased cart

Fig 6-17 This typical light duty cart is drawn as an outline with the shaded parts showing the added angle bracing as though you could see them through the material of the cart Because the sheet metal sidewalls and top angles increase both the strength and rigidity

of these carts, it is possible to use one, instead of build- ingfiom scratch, by extending the vertical members all the way to the cart's bottom The addition of horizon- tal angle bracing brings the cart up to nominal strength, suficient for its planned purpose The addi- tional cost of the cart ofsets any savings in metal pur- chased, but this fabrication scheme can simplifj, the cart's construction for those in a hurry

The I -inch Furnace Burner

The 1-inch jet ejector burner is used in 14-inch ID or larger forges or aluminum and bronze hobby furnaces It has the same high flame temperature and fuel saving char- acteristics of the smaller burners

Fig 7-1 Mixing area and end cap of the 1 -inch burner

You will be referred back to the existing instructions where they apply, but the furnace burner is a more streamlined design than the first two burners The end cap (part #4) that houses the gas accelerator assembly can be aimed, and the accelerator position is locked with a pressure nut (part #18) The ability to run well two differ- ent MIG tip sizes (.035-inch and 040-inch) allows splendid control over a long pres- sure range The air intakes and choke sleeve, are fully beveled Because it is meant for use in furnaces, an ignition opening is included in the choke assembly If you have already built either of the first two burners, you won't need detailed instructions for many of the tasks in this plan If you are starting with the burner described here, it will be necessary for you to refer to both of the previous burner chapters, often The burner's gas accelerator assembly is another silver brazed variation, but in the next chapter there is a simple threaded version

Materials list

(1A) 1 112-inch #316 SS pipe 3-inch long

(1B) 1 114-inch sc # 40 black wall pipe 1 114-inch long

(2) 1-inch sc #40 black wall pipe 13-inches long

(3) 1 114-inch black wall pipe 4 112-inches long

(4) 314 x 114-inch NPT bushing (steel preferred)

Gas Burners 7

(5) One #10 114-20 x 112-inch long thumbscrew, flat washer

(6) 118-inch pipe nipple 40r 6-inches long

(7) A 035-inch and a 040-inch MIG welding contact tip 1 112-inch long

(8) 114 NPT gas rated ball valve

(9) 114 x 90" street ell or elbow

(10) 114 NPT short nipple (preferably hex, two of them if #9 is a street ell)

(1 1) 118 x 114 NPT bell reducer (or threaded bushing)

(12) 9/16-18 LH thread to 114 MPT Outlet Bushing

(13) 10-24 x 15164" brass threaded wood insert

( 14) 118 NPT brass coupling

(15) Six # 10 x 24 x 114-inch SS set screws

(16) Six # 8 x 32 x 114-inch SS set screws

(17) 118-inch X 1-inch long brass pipe nipple

(18) 118 x 114 NPT steel or brass bushing

( 19) Butane fireplace lighter (recommended)

One sheet of #I20 sand paper

Silver braze

Gas rated sealant or Teflon tape

Tool list:

You need everything from the Chapter 3 tool list along with the following:

(A) A hand torch

(B) Hacksaw with fine-toothed blade

(C) These drill bit sizes instead of what Chapter t3 calls for: a # 7, a #21, a # 29, two 118-inch, a letter "M" or 15164-inch, 13132-inch, a 318-inch or 5116 bit (see Step 7, alternate method)

(D) # 10 x 20 starting tap

(E) 10-inch medium coarse square file

(F) Die grinder recommended

(G) 5132 or 3116-inch round file (recommended)

I Assembling the burner nozzle, parts # I A, # I B, and # I 6

This step is similar to the instructions given in Chapter 3 except for the size of parts The 1 114-inch galvanized pipe (part # 1B) fits loosely over the 1-inch pipe (part # 2) Furthermore, it won't fit within the SS pipe used for the nozzle (part #1A) The solution to both of these problems is to cut the 1 118-inch spacer at the weld seam and compress it Use the hacksaw or a cutoff wheel, then file the opening a little wider (lose about 118-inch)

The I -inch Furnace Burner

Follow the sanding instructions given in step two of Chapter 3 with this burner

In order to make the ignition opening practical, a thumbscrew slot is needed, and the choke sleeve mounted pressure screw is not an option Cut a piece of 1 114-inch pipe

4 112-inches long Scribe a straight line down the length of the pipe Measure 112- inch in from one of the pipe's ends, then center punch the marks Continue marking and center punching at intervals of 3116-inch to within 1-inch of the other end Then, drill 118-inch pilot holes Enlarge the holes with the #21 bit Grind and file the row of holes into a smooth sided slot The 1 114-inch pipe should slide freely on the 1-inch pipe Review Chapter 3, Step 3 for more elaborate instructions on accom- plishing these tasks Or, you can drill a 3116-inch hole at both ends of the proposed slot, cut down the scribed line with a cutoff wheel, change over to a thin grinding wheel and cut a deep "V" groove into the narrow slot, turn the wheel up to right angles and grind a 114-inch slot into the groove As always, finish the ends with a file Follow the instructions in Chapter 3 for preparing the back of the burner tube to achieve a sliding fit After you find a place where the choke sleeve slides freely, use the ink marker to make a line down the length of its slot while it is sitting in this area Scribe a line from the end of the pipe, down through the middle of the inked line Leave the ink to remind yourself that this will be the rib that the slot runs over This rib should be kept a minimum of 114-inch wide

The larger bushing (part # 4) should need no preparation If it does not slip easily into the burner tube (part #2) look for any remains of the internal weld ridge that have not been filed down, or burrs from cutting, that need to be filed away If the part still will not fit, file the threads until it does You can mount the part in the drill by using the 114 x 118-inch bushing and pipe nipple Then spin the large bushing under

a sander Next, prepare the 118 x 114 NPT bushing (part # 18) using the instructions

in Step 4 of Chapter 4

5 Installing the thumbscrew, parts #2 & # 5

Place the sleeve on the 1-inch pipe, centered over the ink line, with its back edge 114- inch in from the pipe edge (the 1-inch area faces forward of the slot and the 112-inch area is back of it) Scribe a cross line in the center of the forward end of its slot for a thumbscrew hole

Remove the choke sleeve, and center punch the mark Drill a 118-inch pilot hole, and enlarge the hole with the # 21 bit, then thread the hole with a # 10 1/4-20 tap Reassemble the choke and tighten the thumbscrew Use one or two small flat washers with the thumbscrew to create a shoulder Note the number of excess threads inside the burner tube and remove them Reassemble your parts (there is a more elaborate explanation of these steps in Chapter 3, Step 5

Gas Burners 7

6 Placing the aiming screws, parts #2, #4, 1 5, & 18

Measure the length that the bushing will sit inside the burner tube, and mark two

places on the scribed and inked line One place will be 5116-inch back from the for-

ward end of the bushing, and the other place will be 118-inch from the back edge of

the burner tube Use the choke to help as you scribe the two lines around the pipe's

circumference The six aiming screws used on the forward row must have their faces

smoothed (see Chapter 3, Step 1, last paragraph) The three holding setscrews in the

back row are left sharp

Insert the bushing into the end of the burner and trap it with the setscrews Just

run them up to touch it Do not tighten them down yet Rotate the bushing until one

of the points of its hex head is lined up with the scribed choke sleeve line Using the

angle, scribe the other five lines longitudinally on the burner tube Center punch all

six places on the forward line where it intersects the longitudinal lines, but only cen-

ter punch every other hole of the back line The three setscrews that are placed in the

back only hold the bushing centered, while the front six screws are used for aiming

Drill the three back holes with a # 29 bit and tap them for # 8-32 setscrews Drill the

six front holes with a # 21 bit and tap them for # 10-32 set screws Clean up all burrs

and install the setscrews Place the 1-inch bushing into the burner tube, with the

setscrews loose gently tighten the three back screws until it is trapped Hold the tube

up to a light source and look down the barrel to see if the bushing is centered If it is,

tighten the screws until they are just touching Leave the aiming screws loose

Lay out the air openings (part # 2)by measuring the length of the threaded portion

of the 1 x 114 NPT bushing, and make a mark 118-inch further distant from the pipe's

edge Slide the choke back to the mark, lock it in position, and scribe a circular line

Now slide the choke forward 2 318-inches and scribe a second line These two lines

represent the forward and rear edges of the row of holes Loosen the set screws just

enough to rotate the end cap until the points of its hex head are midway between the

six forward sets screws Scribe new lines forward from the hex points Make a mark

every 3116-inch starting at the back circular line and ending at the forward circular

Fig 7-2 Three of the forward row of set screw holes and two of the back set screw holes, with one line of set screw holes just visible at the tube edge, areplaced in the back scribe marks Forward of these, and centered between them are the scribed and center punched layouts for

drilling three of the six air openings Two com- plete lines atfi-ont and back of these rows have

no punch marks, and represent the ends of the openings A single hole forward is used for the thumbscrew Fig 3-7 demonstrates how the choke sleeve is first used to help lay out a drilling pattern

The I -inch Furnace Burner

line Use the choke to help scribe the new lines around the pipe's circumference Remove the choke sleeve and thumbscrew Center punch the intersections of all the lines except for the forward and back lines at the air opening's edges (the two origi- nal lines) Scribe longitudinal lines 3116-inch on either side of the longitudinal cen- terlines These two outer lines and the forward line make the edges of the air open- ings

Drill a 118-inch pilot hole in each punch-mark, and enlarge all the holes to 114- inch Then, drill them out to 318-inch Grind and file the row of holes into slots, then file the forward edges of the slots into squares

Or, drill 5116-inch holes at both end punch-marks and in a center punch-mark Then, use the cutoff wheel, placed just inside the outer longitudinal lines to cut between (but not into) the forward and back holes Do not try to cut all the way to the slot ends Hammer out the two weakened "slugs" of left over material within the slots File the forward ends of the slots into squares

Fig 7-3 The cutofjr wheel on a 4

1/2-inch angle grinder has pene-

trated the first and middle 5/16-

inch holes, and will be taken to the

middle of the last hole Note that

the back side of the blade is even

with the scribed line Next, the

blade will cut away the inside of the

other line Care must be taken not

to cut beyond the centers of the end

er in a vice, in the vertical position File the backs of the air intakes square and even with the end of the bushing In order to maintain a good view of the work, you should rotate the burner for each opening

Now, tilt the burner back at an angle in the vice and bevel the back of the intake with the square file and grinder Bevel all six openings this way Each bevel's knife- edge meets the circular edge of the bushing The squared and beveled ends of the air openings promote laminar flow Reverse the burner in the vice and bevel the inside

of the air intake's forward edges in the same manner that you just used to make out-